+++ /dev/null
-/*
- * Copyright (C) 2008 Mathieu Desnoyers
- * Copyright (C) 2009 Pierre-Marc Fournier
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- *
- * Ported to userspace by Pierre-Marc Fournier.
- */
-
-//ust// #include <linux/module.h>
-//ust// #include <linux/mutex.h>
-//ust// #include <linux/types.h>
-//ust// #include <linux/jhash.h>
-//ust// #include <linux/list.h>
-//ust// #include <linux/rcupdate.h>
-//ust// #include <linux/tracepoint.h>
-//ust// #include <linux/err.h>
-//ust// #include <linux/slab.h>
-//ust// #include <linux/immediate.h>
-
-#include <errno.h>
-
-#include "kernelcompat.h"
-#include "tracepoint.h"
-#include "usterr.h"
-#include "list.h"
-
-//extern struct tracepoint __start___tracepoints[] __attribute__((visibility("hidden")));
-//extern struct tracepoint __stop___tracepoints[] __attribute__((visibility("hidden")));
-
-/* Set to 1 to enable tracepoint debug output */
-static const int tracepoint_debug;
-
-/* libraries that contain tracepoints (struct tracepoint_lib) */
-static LIST_HEAD(libs);
-
-/*
- * tracepoints_mutex nests inside module_mutex. Tracepoints mutex protects the
- * builtin and module tracepoints and the hash table.
- */
-static DEFINE_MUTEX(tracepoints_mutex);
-
-/*
- * Tracepoint hash table, containing the active tracepoints.
- * Protected by tracepoints_mutex.
- */
-#define TRACEPOINT_HASH_BITS 6
-#define TRACEPOINT_TABLE_SIZE (1 << TRACEPOINT_HASH_BITS)
-static struct hlist_head tracepoint_table[TRACEPOINT_TABLE_SIZE];
-
-/*
- * Note about RCU :
- * It is used to to delay the free of multiple probes array until a quiescent
- * state is reached.
- * Tracepoint entries modifications are protected by the tracepoints_mutex.
- */
-struct tracepoint_entry {
- struct hlist_node hlist;
- void **funcs;
- int refcount; /* Number of times armed. 0 if disarmed. */
- char name[0];
-};
-
-struct tp_probes {
- union {
-//ust// struct rcu_head rcu;
- struct list_head list;
- } u;
- void *probes[0];
-};
-
-static inline void *allocate_probes(int count)
-{
- struct tp_probes *p = kmalloc(count * sizeof(void *)
- + sizeof(struct tp_probes), GFP_KERNEL);
- return p == NULL ? NULL : p->probes;
-}
-
-//ust// static void rcu_free_old_probes(struct rcu_head *head)
-//ust// {
-//ust// kfree(container_of(head, struct tp_probes, u.rcu));
-//ust// }
-
-static inline void release_probes(void *old)
-{
- if (old) {
- struct tp_probes *tp_probes = container_of(old,
- struct tp_probes, probes[0]);
-//ust// call_rcu_sched(&tp_probes->u.rcu, rcu_free_old_probes);
- synchronize_rcu();
- kfree(tp_probes);
- }
-}
-
-static void debug_print_probes(struct tracepoint_entry *entry)
-{
- int i;
-
- if (!tracepoint_debug || !entry->funcs)
- return;
-
- for (i = 0; entry->funcs[i]; i++)
- printk(KERN_DEBUG "Probe %d : %p\n", i, entry->funcs[i]);
-}
-
-static void *
-tracepoint_entry_add_probe(struct tracepoint_entry *entry, void *probe)
-{
- int nr_probes = 0;
- void **old, **new;
-
- WARN_ON(!probe);
-
- debug_print_probes(entry);
- old = entry->funcs;
- if (old) {
- /* (N -> N+1), (N != 0, 1) probes */
- for (nr_probes = 0; old[nr_probes]; nr_probes++)
- if (old[nr_probes] == probe)
- return ERR_PTR(-EEXIST);
- }
- /* + 2 : one for new probe, one for NULL func */
- new = allocate_probes(nr_probes + 2);
- if (new == NULL)
- return ERR_PTR(-ENOMEM);
- if (old)
- memcpy(new, old, nr_probes * sizeof(void *));
- new[nr_probes] = probe;
- new[nr_probes + 1] = NULL;
- entry->refcount = nr_probes + 1;
- entry->funcs = new;
- debug_print_probes(entry);
- return old;
-}
-
-static void *
-tracepoint_entry_remove_probe(struct tracepoint_entry *entry, void *probe)
-{
- int nr_probes = 0, nr_del = 0, i;
- void **old, **new;
-
- old = entry->funcs;
-
- if (!old)
- return ERR_PTR(-ENOENT);
-
- debug_print_probes(entry);
- /* (N -> M), (N > 1, M >= 0) probes */
- for (nr_probes = 0; old[nr_probes]; nr_probes++) {
- if ((!probe || old[nr_probes] == probe))
- nr_del++;
- }
-
- if (nr_probes - nr_del == 0) {
- /* N -> 0, (N > 1) */
- entry->funcs = NULL;
- entry->refcount = 0;
- debug_print_probes(entry);
- return old;
- } else {
- int j = 0;
- /* N -> M, (N > 1, M > 0) */
- /* + 1 for NULL */
- new = allocate_probes(nr_probes - nr_del + 1);
- if (new == NULL)
- return ERR_PTR(-ENOMEM);
- for (i = 0; old[i]; i++)
- if ((probe && old[i] != probe))
- new[j++] = old[i];
- new[nr_probes - nr_del] = NULL;
- entry->refcount = nr_probes - nr_del;
- entry->funcs = new;
- }
- debug_print_probes(entry);
- return old;
-}
-
-/*
- * Get tracepoint if the tracepoint is present in the tracepoint hash table.
- * Must be called with tracepoints_mutex held.
- * Returns NULL if not present.
- */
-static struct tracepoint_entry *get_tracepoint(const char *name)
-{
- struct hlist_head *head;
- struct hlist_node *node;
- struct tracepoint_entry *e;
- u32 hash = jhash(name, strlen(name), 0);
-
- head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)];
- hlist_for_each_entry(e, node, head, hlist) {
- if (!strcmp(name, e->name))
- return e;
- }
- return NULL;
-}
-
-/*
- * Add the tracepoint to the tracepoint hash table. Must be called with
- * tracepoints_mutex held.
- */
-static struct tracepoint_entry *add_tracepoint(const char *name)
-{
- struct hlist_head *head;
- struct hlist_node *node;
- struct tracepoint_entry *e;
- size_t name_len = strlen(name) + 1;
- u32 hash = jhash(name, name_len-1, 0);
-
- head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)];
- hlist_for_each_entry(e, node, head, hlist) {
- if (!strcmp(name, e->name)) {
- printk(KERN_NOTICE
- "tracepoint %s busy\n", name);
- return ERR_PTR(-EEXIST); /* Already there */
- }
- }
- /*
- * Using kmalloc here to allocate a variable length element. Could
- * cause some memory fragmentation if overused.
- */
- e = kmalloc(sizeof(struct tracepoint_entry) + name_len, GFP_KERNEL);
- if (!e)
- return ERR_PTR(-ENOMEM);
- memcpy(&e->name[0], name, name_len);
- e->funcs = NULL;
- e->refcount = 0;
- hlist_add_head(&e->hlist, head);
- return e;
-}
-
-/*
- * Remove the tracepoint from the tracepoint hash table. Must be called with
- * mutex_lock held.
- */
-static inline void remove_tracepoint(struct tracepoint_entry *e)
-{
- hlist_del(&e->hlist);
- kfree(e);
-}
-
-/*
- * Sets the probe callback corresponding to one tracepoint.
- */
-static void set_tracepoint(struct tracepoint_entry **entry,
- struct tracepoint *elem, int active)
-{
- WARN_ON(strcmp((*entry)->name, elem->name) != 0);
-
- /*
- * rcu_assign_pointer has a smp_wmb() which makes sure that the new
- * probe callbacks array is consistent before setting a pointer to it.
- * This array is referenced by __DO_TRACE from
- * include/linux/tracepoints.h. A matching smp_read_barrier_depends()
- * is used.
- */
- rcu_assign_pointer(elem->funcs, (*entry)->funcs);
- elem->state__imv = active;
-}
-
-/*
- * Disable a tracepoint and its probe callback.
- * Note: only waiting an RCU period after setting elem->call to the empty
- * function insures that the original callback is not used anymore. This insured
- * by preempt_disable around the call site.
- */
-static void disable_tracepoint(struct tracepoint *elem)
-{
- elem->state__imv = 0;
- rcu_assign_pointer(elem->funcs, NULL);
-}
-
-/**
- * tracepoint_update_probe_range - Update a probe range
- * @begin: beginning of the range
- * @end: end of the range
- *
- * Updates the probe callback corresponding to a range of tracepoints.
- */
-void tracepoint_update_probe_range(struct tracepoint *begin,
- struct tracepoint *end)
-{
- struct tracepoint *iter;
- struct tracepoint_entry *mark_entry;
-
- mutex_lock(&tracepoints_mutex);
- for (iter = begin; iter < end; iter++) {
- mark_entry = get_tracepoint(iter->name);
- if (mark_entry) {
- set_tracepoint(&mark_entry, iter,
- !!mark_entry->refcount);
- } else {
- disable_tracepoint(iter);
- }
- }
- mutex_unlock(&tracepoints_mutex);
-}
-
-/*
- * Update probes, removing the faulty probes.
- */
-static void tracepoint_update_probes(void)
-{
- /* Core kernel tracepoints */
-//ust// tracepoint_update_probe_range(__start___tracepoints,
-//ust// __stop___tracepoints);
- /* tracepoints in modules. */
- lib_update_tracepoints();
- /* Update immediate values */
- core_imv_update();
-//ust// module_imv_update();
-}
-
-static void *tracepoint_add_probe(const char *name, void *probe)
-{
- struct tracepoint_entry *entry;
- void *old;
-
- entry = get_tracepoint(name);
- if (!entry) {
- entry = add_tracepoint(name);
- if (IS_ERR(entry))
- return entry;
- }
- old = tracepoint_entry_add_probe(entry, probe);
- if (IS_ERR(old) && !entry->refcount)
- remove_tracepoint(entry);
- return old;
-}
-
-/**
- * tracepoint_probe_register - Connect a probe to a tracepoint
- * @name: tracepoint name
- * @probe: probe handler
- *
- * Returns 0 if ok, error value on error.
- * The probe address must at least be aligned on the architecture pointer size.
- */
-int tracepoint_probe_register(const char *name, void *probe)
-{
- void *old;
-
- mutex_lock(&tracepoints_mutex);
- old = tracepoint_add_probe(name, probe);
- mutex_unlock(&tracepoints_mutex);
- if (IS_ERR(old))
- return PTR_ERR(old);
-
- tracepoint_update_probes(); /* may update entry */
- release_probes(old);
- return 0;
-}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_probe_register);
-
-static void *tracepoint_remove_probe(const char *name, void *probe)
-{
- struct tracepoint_entry *entry;
- void *old;
-
- entry = get_tracepoint(name);
- if (!entry)
- return ERR_PTR(-ENOENT);
- old = tracepoint_entry_remove_probe(entry, probe);
- if (IS_ERR(old))
- return old;
- if (!entry->refcount)
- remove_tracepoint(entry);
- return old;
-}
-
-/**
- * tracepoint_probe_unregister - Disconnect a probe from a tracepoint
- * @name: tracepoint name
- * @probe: probe function pointer
- *
- * We do not need to call a synchronize_sched to make sure the probes have
- * finished running before doing a module unload, because the module unload
- * itself uses stop_machine(), which insures that every preempt disabled section
- * have finished.
- */
-int tracepoint_probe_unregister(const char *name, void *probe)
-{
- void *old;
-
- mutex_lock(&tracepoints_mutex);
- old = tracepoint_remove_probe(name, probe);
- mutex_unlock(&tracepoints_mutex);
- if (IS_ERR(old))
- return PTR_ERR(old);
-
- tracepoint_update_probes(); /* may update entry */
- release_probes(old);
- return 0;
-}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_probe_unregister);
-
-static LIST_HEAD(old_probes);
-static int need_update;
-
-static void tracepoint_add_old_probes(void *old)
-{
- need_update = 1;
- if (old) {
- struct tp_probes *tp_probes = container_of(old,
- struct tp_probes, probes[0]);
- list_add(&tp_probes->u.list, &old_probes);
- }
-}
-
-/**
- * tracepoint_probe_register_noupdate - register a probe but not connect
- * @name: tracepoint name
- * @probe: probe handler
- *
- * caller must call tracepoint_probe_update_all()
- */
-int tracepoint_probe_register_noupdate(const char *name, void *probe)
-{
- void *old;
-
- mutex_lock(&tracepoints_mutex);
- old = tracepoint_add_probe(name, probe);
- if (IS_ERR(old)) {
- mutex_unlock(&tracepoints_mutex);
- return PTR_ERR(old);
- }
- tracepoint_add_old_probes(old);
- mutex_unlock(&tracepoints_mutex);
- return 0;
-}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_probe_register_noupdate);
-
-/**
- * tracepoint_probe_unregister_noupdate - remove a probe but not disconnect
- * @name: tracepoint name
- * @probe: probe function pointer
- *
- * caller must call tracepoint_probe_update_all()
- */
-int tracepoint_probe_unregister_noupdate(const char *name, void *probe)
-{
- void *old;
-
- mutex_lock(&tracepoints_mutex);
- old = tracepoint_remove_probe(name, probe);
- if (IS_ERR(old)) {
- mutex_unlock(&tracepoints_mutex);
- return PTR_ERR(old);
- }
- tracepoint_add_old_probes(old);
- mutex_unlock(&tracepoints_mutex);
- return 0;
-}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_probe_unregister_noupdate);
-
-/**
- * tracepoint_probe_update_all - update tracepoints
- */
-void tracepoint_probe_update_all(void)
-{
- LIST_HEAD(release_probes);
- struct tp_probes *pos, *next;
-
- mutex_lock(&tracepoints_mutex);
- if (!need_update) {
- mutex_unlock(&tracepoints_mutex);
- return;
- }
- if (!list_empty(&old_probes))
- list_replace_init(&old_probes, &release_probes);
- need_update = 0;
- mutex_unlock(&tracepoints_mutex);
-
- tracepoint_update_probes();
- list_for_each_entry_safe(pos, next, &release_probes, u.list) {
- list_del(&pos->u.list);
-//ust// call_rcu_sched(&pos->u.rcu, rcu_free_old_probes);
- synchronize_rcu();
- kfree(pos);
- }
-}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_probe_update_all);
-
-/**
- * tracepoint_get_iter_range - Get a next tracepoint iterator given a range.
- * @tracepoint: current tracepoints (in), next tracepoint (out)
- * @begin: beginning of the range
- * @end: end of the range
- *
- * Returns whether a next tracepoint has been found (1) or not (0).
- * Will return the first tracepoint in the range if the input tracepoint is
- * NULL.
- */
-int tracepoint_get_iter_range(struct tracepoint **tracepoint,
- struct tracepoint *begin, struct tracepoint *end)
-{
- if (!*tracepoint && begin != end) {
- *tracepoint = begin;
- return 1;
- }
- if (*tracepoint >= begin && *tracepoint < end)
- return 1;
- return 0;
-}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_get_iter_range);
-
-static void tracepoint_get_iter(struct tracepoint_iter *iter)
-{
- int found = 0;
-
-//ust// /* Core kernel tracepoints */
-//ust// if (!iter->module) {
-//ust// found = tracepoint_get_iter_range(&iter->tracepoint,
-//ust// __start___tracepoints, __stop___tracepoints);
-//ust// if (found)
-//ust// goto end;
-//ust// }
- /* tracepoints in libs. */
- found = lib_get_iter_tracepoints(iter);
-end:
- if (!found)
- tracepoint_iter_reset(iter);
-}
-
-void tracepoint_iter_start(struct tracepoint_iter *iter)
-{
- tracepoint_get_iter(iter);
-}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_iter_start);
-
-void tracepoint_iter_next(struct tracepoint_iter *iter)
-{
- iter->tracepoint++;
- /*
- * iter->tracepoint may be invalid because we blindly incremented it.
- * Make sure it is valid by marshalling on the tracepoints, getting the
- * tracepoints from following modules if necessary.
- */
- tracepoint_get_iter(iter);
-}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_iter_next);
-
-void tracepoint_iter_stop(struct tracepoint_iter *iter)
-{
-}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_iter_stop);
-
-void tracepoint_iter_reset(struct tracepoint_iter *iter)
-{
-//ust// iter->module = NULL;
- iter->tracepoint = NULL;
-}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_iter_reset);
-
-//ust// #ifdef CONFIG_MODULES
-
-//ust// int tracepoint_module_notify(struct notifier_block *self,
-//ust// unsigned long val, void *data)
-//ust// {
-//ust// struct module *mod = data;
-//ust//
-//ust// switch (val) {
-//ust// case MODULE_STATE_COMING:
-//ust// tracepoint_update_probe_range(mod->tracepoints,
-//ust// mod->tracepoints + mod->num_tracepoints);
-//ust// break;
-//ust// case MODULE_STATE_GOING:
-//ust// tracepoint_update_probe_range(mod->tracepoints,
-//ust// mod->tracepoints + mod->num_tracepoints);
-//ust// break;
-//ust// }
-//ust// return 0;
-//ust// }
-
-//ust// struct notifier_block tracepoint_module_nb = {
-//ust// .notifier_call = tracepoint_module_notify,
-//ust// .priority = 0,
-//ust// };
-
-//ust// static int init_tracepoints(void)
-//ust// {
-//ust// return register_module_notifier(&tracepoint_module_nb);
-//ust// }
-//ust// __initcall(init_tracepoints);
-
-//ust// #endif /* CONFIG_MODULES */
-
-/*
- * Returns 0 if current not found.
- * Returns 1 if current found.
- */
-int lib_get_iter_tracepoints(struct tracepoint_iter *iter)
-{
- struct tracepoint_lib *iter_lib;
- int found = 0;
-
-//ust// mutex_lock(&module_mutex);
- list_for_each_entry(iter_lib, &libs, list) {
- if (iter_lib < iter->lib)
- continue;
- else if (iter_lib > iter->lib)
- iter->tracepoint = NULL;
- found = marker_get_iter_range(&iter->tracepoint,
- iter_lib->tracepoints_start,
- iter_lib->tracepoints_start + iter_lib->tracepoints_count);
- if (found) {
- iter->lib = iter_lib;
- break;
- }
- }
-//ust// mutex_unlock(&module_mutex);
- return found;
-}
-
-void lib_update_tracepoints(void)
-{
- struct tracepoint_lib *lib;
-
-//ust// mutex_lock(&module_mutex);
- list_for_each_entry(lib, &libs, list)
- tracepoint_update_probe_range(lib->tracepoints_start,
- lib->tracepoints_start + lib->tracepoints_count);
-//ust// mutex_unlock(&module_mutex);
-}
-
-static void (*new_tracepoint_cb)(struct tracepoint *) = NULL;
-
-void tracepoint_set_new_tracepoint_cb(void (*cb)(struct tracepoint *))
-{
- new_tracepoint_cb = cb;
-}
-
-static void new_tracepoints(struct tracepoint *start, struct tracepoint *end)
-{
- if(new_tracepoint_cb) {
- struct tracepoint *t;
- for(t=start; t < end; t++) {
- new_tracepoint_cb(t);
- }
- }
-}
-
-int tracepoint_register_lib(struct tracepoint *tracepoints_start, int tracepoints_count)
-{
- struct tracepoint_lib *pl;
-
- pl = (struct tracepoint_lib *) malloc(sizeof(struct tracepoint_lib));
-
- pl->tracepoints_start = tracepoints_start;
- pl->tracepoints_count = tracepoints_count;
-
- /* FIXME: maybe protect this with its own mutex? */
- mutex_lock(&tracepoints_mutex);
- list_add(&pl->list, &libs);
- mutex_unlock(&tracepoints_mutex);
-
- new_tracepoints(tracepoints_start, tracepoints_start + tracepoints_count);
-
- /* FIXME: update just the loaded lib */
- lib_update_tracepoints();
-
- DBG("just registered a tracepoints section from %p and having %d tracepoints", tracepoints_start, tracepoints_count);
-
- return 0;
-}
-
-int tracepoint_unregister_lib(struct tracepoint *tracepoints_start, int tracepoints_count)
-{
- /*FIXME: implement; but before implementing, tracepoint_register_lib must
- have appropriate locking. */
-
- return 0;
-}
projects / ust.git / blobdiff